Tip-resistant valve plugs

A pressure sensitive valve assembly comprising an orifice surround, a pressure relief spring, and a tip-resistant valve plug comprising a valve head, first and second retention legs, and an anti-tip fin, wherein:

• the orifice surround comprises a fluid flow orifice;
• the valve head defines a fluid barrier;
• the anti-tip fin and the retention legs extend from the same side of valve head;
• the pressure relief spring contacts the retention legs of the tip-resistant valve plug and the orifice surround and exerts a force on the tip-resistant valve plug in a direction corresponding to moving the tip-resistant valve plug toward a closed position;
• and
• (i) the anti-tip fin comprises a groove that allows the valve head to flex along a longitudinal fin axis;
• (ii) the anti-tip fin extends from the side of the valve head to a fin height dimension that is greater than a relief spring compression dimension caused by the tip-resistant valve moving between a closed position and an open position;
• or (iii) the valve head has a smaller moment of inertia evaluated in a direction the anti-tip fin extends across the valve head than a moment of inertia evaluated in a direction normal to the direction the anti-tip fin extends across the valve head.